Mathematics
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OpenStudy (anonymous):
solve the equation 2cos^2θ-3cosθ+1=0, 0≤θ<0
I believe it has to be in radians. If you could rather help me to the answer, that would be amazing!
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OpenStudy (anonymous):
\[2\cos ^{2}\theta-3\cos \theta+1=0\]
OpenStudy (anonymous):
\[0\le \theta <0\]
OpenStudy (anonymous):
can you provide more info like answer choices and what are we doing with this problem explain a little
OpenStudy (anonymous):
There are no answer choices
OpenStudy (anonymous):
that is alright, so what is the problem asking for us to do?
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OpenStudy (anonymous):
just to solve for theta
OpenStudy (anonymous):
let me ask you how would you solve for x? what steps must taken? I know the answer I want to see if you know I am trying to help here
OpenStudy (anonymous):
would it be simplified to \[\cos \theta(\cos \theta+1)=2/3\]?
OpenStudy (anonymous):
yes now what?
OpenStudy (anonymous):
how do you get theda by itself
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OpenStudy (anonymous):
This is where I become lost.
OpenStudy (anonymous):
wait, would you use arccos to 2/3?
OpenStudy (anonymous):
\[\cos \theta+1=\cos^{-1} (2/3)\]
OpenStudy (anonymous):
keep going
OpenStudy (anonymous):
cos th+1 and sub -1
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OpenStudy (anonymous):
than divide by cos so you have theda =
OpenStudy (anonymous):
so \[\theta=\cos^{-1} (2/3)-1/\]
OpenStudy (anonymous):
\[\theta=\cos^{-1} (2/3)-1/\cos\]
OpenStudy (anonymous):
yes now it is not done what can be to 2/3-1?
OpenStudy (anonymous):
-1/3?
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OpenStudy (anonymous):
yes so what is the final answer now
OpenStudy (anonymous):
Does cos and cos^-1 cancel out leaving only -1/3?
OpenStudy (anonymous):
no
OpenStudy (anonymous):
Dang.. I do not know what to do after this.
OpenStudy (anonymous):
you are done
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OpenStudy (anonymous):
\[\theta=\cos^{-1} (-1/3)/\cos\]
Nothing need to be placed next to cos?
OpenStudy (anonymous):
no
OpenStudy (anonymous):
Ok. Thank you :)
OpenStudy (anonymous):
did you get what it was asking for my itself? if yes than you are finished
OpenStudy (anonymous):
Yes :)